"The bank is taking additional steps to safeguard sensitive or confidential information, though it not seeing unusual fraud activity at this time," company spokeswoman Trish Wexler told the website.

On Wednesday, Bloomberg reported that the FBI was investigating an alleged cyberattack that affected five U.S. banks at the beginning of August, including JP Morgan Chase & Co., identified in the article as the target of the attack.

In addition to the FBI, a number of outside security companies have been brought in to investigate the cyberattack. The NSA is also reported to have been called in to help with the investigation.

Security experts have speculated that the attack may have originated from a foreign government rather than a gang of criminal hackers motivated by financial gain. The Russian government has been touted as a possible originator of the hack, which may have been in retaliation for recent sanctions levied on Russia by the U.S. government over the crisis in Ukraine. The news comes as tensions between Russia and Ukraine have reached a new high with geopolitical expert Ian Bremmer of Eurasia Group tweeting Thursday morning: "Russia, Ukraine now at war."

In a statement to the New York Times, JPMorgan spokeswoman Patricia Wexler said: "Companies of our size unfortunately experience cyberattacks nearly every day, we have multiple layers of defense to counteract any threats and constantly monitor fraud levels.”

Last week, JPMorgan was revealed to have been the target in an email phishing campaign that attempted to collect customer information. The "smash and grab" campaign attempted to scam JPMorgan customers into handing over their bank information, as well as infecting computers with viruses. It's currently unclear whether this is related to the latest cyber-attack.